Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 919 · 40 questions

Remember (Find the topic, use the idea): Find the topic: circuit, safety, formula, component, program, sensor or IoT. Use that lesson’s rule — complete loop, V = I × R, P = V × I, last command wins, true → if part. Safety answers are always: low voltage, dry hands, an adult, never the mains.

1. 1.True or false: a microcontroller has a built-in keyboard. (a) False (b) True
2. 2.💡 In a series circuit, how many paths does the current have? (a) none (b) one for each bulb (c) one (d) two
3. 3.🤖 if (light < 400) { lamp ON } else { lamp OFF }
   The light sensor reads 277. What happens? (a) lamp OFF (b) lamp ON
4. 4.⚠️ Is it safe to poke things in a socket? (a) safe (b) not safe
5. 5.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
6. 6.🗺️ In an input → process → output plan, is “a light level reading” the input, the process or the output? (a) process (b) output (c) input
7. 7.🗺️ In an input → process → output plan, is “the pump turns on” the input, the process or the output? (a) process (b) output (c) input
8. 8.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = R ÷ V (c) I = V + R (d) I = V × R
9. 9.🔺 A current of 0.5 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
10. 10.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) gets bigger (c) becomes zero (d) gets smaller
11. 11.🧩 A capacitor in a circuit can … (a) make light (b) store charge briefly (c) spin a wheel (d) measure heat
12. 12.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
13. 13.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) share it with friends (b) post it online (c) type it all in (d) ask a parent first
14. 14.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) + (positive) (b) − (negative)
15. 15.💡 A blue LED uses 3 V and should get 20 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
16. 16.Which of these is an input? (a) an LED (b) a motor (c) a sound sensor (d) a water pump
17. 17.⚠️ Is it safe to use mains for a project? (a) not safe (b) safe
18. 18.🌈 A resistor has the colour bands red, red, orange. What is its value (in ohms)?
19. 19.🤖 if (temperature > 34) { show “Hot” } else if (temperature > 25) { show “Warm” } else { show “Cool” }
    The temperature is 41 °C. What is shown? (a) Warm (b) Cool (c) Hot
20. 20.📏 In the water-pipe picture of a circuit, voltage is like … (a) the water tank lid (b) the water pressure (c) the pipe colour (d) the tap handle
21. 21.💡 An LED is joined to a 6 V battery through a 1000 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) may burn out (b) lights up (c) does not light
22. 22.⚡ A device works on 6 V and takes 2 A. What is its power (in watts)? =
23. 23.⚡ What do we call a flow of electric charge through a wire? (a) a magnet (b) friction (c) sound (d) electric current
24. 24.🔺 A 3 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
25. 25.💡 2 identical bulbs are joined in parallel across a 1.5 V battery (ideal wires). How many volts does each bulb get? =
26. 26.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
27. 27.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
28. 28.🤖 if (distance < 10) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 13 cm. What happens? (a) buzzer beeps (b) buzzer is silent
29. 29.⚡ A solar panel changes which kind of energy into electricity? (a) light energy (b) chemical energy (c) wind energy (d) sound energy
30. 30.Which of these is an insulator? (a) a graphite rod (b) a glass marble (c) a safety pin (d) an iron nail
31. 31.True or false: on an LED, the longer leg is the anode (+). (a) True (b) False
32. 32.🔋 2 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
33. 33.💡 An LED is joined to a 5 V battery through a 470 Ω resistor; the leg next to the flat edge of its rim goes to the + side. What happens? (a) lights up (b) may burn out (c) does not light
34. 34.🌈 A resistor has the colour bands white, yellow, black. What is its value (in ohms)?
35. 35.🔺 A current of 0.1 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
36. 36.🔁 total = 0
    for i = 1 to 6 { total = total + i }
    What is total at the end?
37. 37.Which of these is a conductor? (a) a plastic straw (b) an iron nail (c) a glass marble (d) a cotton thread
38. 38.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
39. 39.Which of these is true of a parallel circuit? (a) a single current path (b) each gets the full volts (c) bulbs share the voltage (d) one bulb out, all go out
40. 40.Which of these is a risky habit? (a) turn off unused gadgets (b) cover unused cameras (c) keep factory passwords (d) change default passwords

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